RoadBikeReview.com's Forum Archives - Components


Archive Home >> Components(1 2 3 4 5 6 7 8 9 10 )


couple questions about upgrading to 8 or 9 speed.(16 posts)

couple questions about upgrading to 8 or 9 speed.rufus
Aug 20, 2002 7:34 AM
my only bike is a 1989 specialized sirrus, with 7 speed downtube shifters. i recently had it in the shop to fix a clunk in the drivetrain, which was finally solved by replacing my chain and five rear cogs with newer hyperglide ones.

this works, but shifting is a bit off, because of the mix of hyperglide and older uniglide cogs. i can't go to a full hyperglide set, because my freehub uses a threaded cog, not a lockring. however, while diagnosing the problem, my mechanic tried a 9 speed wheel, which fit right into my frame, although the spacing isn't 130mm. so i've got it into my head to possibly upgrade to 9 speed; all i'll need is a new freehub, cassette, chain, and shifters, and have my rear wheel re-dished for the wider freehub, probably $120-$150. would the extra dish cause problems(i'm a bit heavy, but it is a 36 spoke wheel), or should i go for a newer 9 speed hub, which would raise the cost a bit, as i'd need my whole wheel rebuilt, or is the result just the same either way?

i've emailed sheldon brown, and i can get a 7 speed hub cheap, put the freehub from that onto my current hub, and put on a 7 speed hyperglide cassette, maybe $60 total cost. alternatively, on his site, he says that you can put 8 cogs from a 9 speed cassette on a 7 speed hub, but you'll need the 9 speed chain and shifters.

if i'm not mistaken, don't 7 speed downtube shifters have a phantom 8th click that i can use to shift an 8 speed cassette? if so, then all i'd need is a 9 speed chain and cassette, maybe $30 dollars more for a $90 total cost.
re: couple questions about upgrading to 8 or 9 speed.str8dum1
Aug 20, 2002 7:44 AM
With a bike that old, i would spend as little as possible. Just get a new 8 speed sachs freewheel from performance or excel etc. they shift well.
i don't think an 8 speed freewheel will fit.rufus
Aug 20, 2002 8:02 AM
my impressions from the sheldon brown site are that you need a nine speed cassette, for the narrower cogs and spacing, and just remove one cog for it to fit on the seven speed freehub. and i still have the question of whether my seven speed shifters will shift the eighth gear.

i love this bike; sure its old, but it rides great, even one of the guys at the bike shop remarked about how smooth it rode.
sorry, screwed up.(nm)rufus
Aug 20, 2002 8:03 AM
i don't think an 8 speed cassette will fit.rufus
Aug 20, 2002 8:02 AM
my impressions from the sheldon brown site are that you need a nine speed cassette, for the narrower cogs and spacing, and just remove one cog for it to fit on the seven speed freehub. and i still have the question of whether my seven speed shifters will shift the eighth gear.

i love this bike; sure its old, but it rides great, even one of the guys at the bike shop remarked about how smooth it rode.
You don't get it.......Rusty Coggs
Aug 20, 2002 11:55 AM
Once you have the correct 7 speed hub,you take a 9 speed cassette and remove a cog and a spacer to make a 8 speed cogset that fits the hub. It STILL HAS 9 SPEED SPACING.and your 7 speed shifters will not shift it even if they had an 8th click. that's because 7 speed cog spacing is 5.0mm and you now have 9 speed or 4.34mm cog spacing. You need 9 speed shifters.You also need to use a 9 speed chain on it. Your shifters will work fine if they have the FRICTION mode.
that's what i'm trying to determine.rufus
Aug 20, 2002 1:21 PM
according to sheldon brown, at least from what i can see, most of the indexing systems have enough room for error that they should be able to shift 8 cogs, even if they are using nine speed spacing. maybe i'm misinterpreting the info on his site. and he just sent me an email, where i asked him about the phantom 8th click on my 7 speed downtube shifters, and whether that would work with this type of 8 speed setup and he said, "bingo!". so i guess it will. i'll find out for sure when i see him on friday.
There's three different topics on this thread.Spoke Wrench
Aug 20, 2002 2:00 PM
No wonder everybody's confused. I'm having a hard time keeping track of it all and I think that I understand what everyone is saying.

First: How to make your bike work the way it used to? Replace your 7-speed freehub body that uses the screw-on small cog with a newer 7-speed freehub body that uses a separate lockring. Then you can use a new 7-speed cassette and your bike will work like when it was new.

Second: How to turn your 7-speed bike into an 8-speed? Two solutions:

The first is to get a whole new wheel or modify your existing wheel to accept an 8-speed freehub body. That way you can buy an 8-speed cassette and use the "Phantom position" on your 7-speed shifter to shift the 8 gears. This is the concept that takes advantage of the "slop" built into the indexing.

The second solution is to upgrade your freehub body to a newer 7-speed freehub body, as above, and buy a 9-speed cassette. Get one of the cheap ones that has all separate cogs. Throw away one of the cogs and you have 8 cogs that will fit onto your 7-speed freehub body. You'll also need a narrower, 9-speed chain. Your shifter is designed to index shift 7 gears over the amount of space where you now have 8 gears. It isn't going to index anymore. You'll have to use the friction shifting mode for this to work.

Despite what anybody else says, even Sheldon Brown, mis mash match parts don't work together as precisely as parts that are designed to work together. You've already discovered that with your mix of cogs on your existing cassette. If it was my bike, I'd much rather have a good operating 7-speed than a cobbled up 8-speed.
spoke wrench, you seem to have the best grasp on what i'm askingrufus
Aug 20, 2002 6:18 PM
i doubt if i'll go with the 8 speed setup. hell, if i gotta buy a 9 speed cogset and chain, i might as well go for the shifters and freehub as well.

as i said, while tracking down my problem, my lbs stuck a 9 speed wheel onto my bike, which fit right in no problem, even though it's not a 130mm spacing. my measurement with just a tape measure said 128mm. do you see any problem upgrading the whole thing to 9 speed? in for a penny, in for a pound.
How long do you plan to keep this bike?Spoke Wrench
Aug 21, 2002 5:40 AM
Most component upgrades don't make economic sense. It's not too hard to put $300.00 into a bike that would sell for about $100.00 after you're done. On the other hand, when you're finished, you'll probably like it better than a bike that you could buy for $300.00. So if this is a bike that you plan to ride forever, it might be one of the exceptions.

New back wheel, cassette, chain and shifters at the minimum. If you stay with down tube shifters, the front doesn't index so you shouldn't have any trouble there. A rear derailleur that old may be so worn that it won't shift precisely enough for the closer 9-speed spacing. Your rear wheel is already living on borrowed time so you might as well plan on replacing it in the near future anyway. It looks to me like the only parts you'd absolutely have to buy that aren't necessary for a functioning 7-speed are the shifters and chain.

On the other hand, 9-speed parts will tend to cost more. I think that I said in one of my other posts "9-speed" is the Japanese word for "expensive."
as long as it will last.rufus
Aug 21, 2002 10:19 AM
it will eventually become a second/bad weather bike, but i've got no plans to ever get rid of it. probably i will keep it 7 speed, as that's the most economical option.
OK, one at a time.Spoke Wrench
Aug 20, 2002 8:35 AM
You currently have the Mark I version of the Shimano freehub. Your LBS put a mis-mash of cogs onto it to get you back on the road, but it doesn't shift to your standards. I'm not surprised. That's what often happens with mix and match parts. It kind'a works, but isn't really up to our standards.

I like Sheldon Brown's suggestion best. It requires buying a new rear hub and a new 7-speed cassette. You have to completely disassemble your current hub and change out your old style free hub body with the one from the new hub that uses a lockring. Then stick on the new cassette and you will be good to go.

I'd beware of the other options you indicated. You may find yourself buying one part after another before you find a combination that works together. 9-speed is the Japanese word for expensive.
i'm going to boston on fridayrufus
Aug 20, 2002 9:59 AM
so i'm gonna stop by harris cyclery and discuss all this with sheldon brown. on his site, he says any of those options will work, but i may have equipment that will pose some problems. but if anyone can figure out the best solution, it would be him.
re: couple questions about upgrading to 8 or 9 speed.tav
Aug 20, 2002 9:28 AM
8 speed and 9 speed freewheels are the same , the width of the 8 and 9 speed cassette are the same, just the 9 speed use a narrower chain, but for the shifters i don't think it will go.
Not all 8 and 9's are the same...Dave Hickey
Aug 20, 2002 9:54 AM
THe first generation 8 speed(uniglide) had the last cog screw in place.
what does your hub look like?jaybird
Aug 21, 2002 10:08 AM
I just rebuilt an old trek 460 and although I could have upgraded to 8 or 9 I just bought a new 7speed sachs freewheel and everything works great. When did the cassette idea come out? I didnt think it was until the early 90s. I guess I'm not sure why they didn't just sell you a new freewheel. some real smooth sachs models are available from QBP for 40 - 50 bucks.